Method of calibration with photoactivatable chemiluminescent matrices

Abstract

Methods for labeling a material are disclosed. The methods comprise combining with the material (a) a photosensitizer capable upon irradiation of generating singlet oxygen and (b) a chemiluminescent compound capable of being activated by singlet oxygen wherein the photosensitizer and the chemiluminescent compound are incorporated in a particulate matrix or a non-particulate solid matrix. The particulate matrix can be solid or fluid. The methods allow for generating delayed luminescence, which can be realized upon irradiation of the matrix. The methods have application to the determination of an analyte in a medium suspected of containing the analyte. One method comprises subjecting a medium suspected of containing an analyte to conditions under which a complex of specific binding pair (sbp) members is formed in relation to the presence of the analyte and determining whether the sbp member complex has formed by employing as a label a single composition having both chemiluminescent and photosensitizer properties. Upon activation of the photosensitizer property singlet oxygen is generated and activates the chemiluminescent property. Compositions and kits are also disclosed.

What is claimed is: 
     
       1. A method for calibrating light intensity emitted by a luminescent composition, said method comprising the steps of: (a) combining in a medium a luminescent composition capable of emitting light upon irradiation and a composition comprising a solid matrix having incorporated therein a photosensitizer capable upon activation of generating singlet oxygen and a chemiluminescent compound capable of being activated by singlet oxygen, one of said compositions when activated by light having a decay time for light emission substantially greater than the decay time for the other,   (b) irradiating said medium to activate said luminescent composition and said composition,   (c) measuring the intensity of light emitted during the decay of the activated composition having the shorter decay time,   (d) measuring the intensity of light emitted after said measuring of step (c) and after at least partial decay of the activated composition having the shorter decay time, and   (e) comparing the intensity of the light emitted during the decay of the activated composition having the shorter decay time with the intensity of light emitted in step (d) to provide for internal calibration.   
     
     
       2. The method of claim 1 wherein steps b and c are repeated prior to step d. 
     
     
       3. The method of claim 1 wherein said activated composition comprising said solid material has the shorter decay time.